In the Victoria Longitudinal Study (VLS), we conduct a series of studies pertaining to the description and explanation of aging-related changes in memory performance. The research derives from the perspective that the magnitude of late-life changes in memory performance may depend substantially on individual differences in underlying information processing and intellectual ability components. Aging-related declines may be greater for some individuals than others, and be associated more with some memory tasks than others. The VLS is also designed to examine three potential mediators of differential change in memory aging: (a) general health, specific disease processes, sensory functioning, and physical characteristics, (b) everyday activities and life style characteristics, and (c) beliefs about memory aging, awareness, and memory self-efficacy. The VLS is designed as a longitudinal sequential study. Three independent samples are recruited at six-year internals. Each sample is tested at three-year intervals. To date, Sample 1 has been tested four times over nine years (1986, n=484; 1989, n=333; 1992, n=250; 1995, n=177). The fifth wave occurs in 1998 (expected n=130). Sample 2 has been tested twice over three years (1993, n=530; 1996, n=405). The present proposal is for the sixth testing of Sample 1 (expected n=97), the third testing of Sample 2 (expected n=303), and the first testing of Sample 3 (expected n=550). Approximately 10 hours of data are collected per participant at each occasion. The test battery includes six categories of variables: (a) memory, (b) information processing components, (c) psychometric abilities, (d) metacognitive and awareness measures, (e) personality, lifestyle activity indicators, and (f) physical health and sensory measures. In sum, the proposed research is designed to examine (a) the extent and trajectories of aging-related changes in a variety of memory phenomena, (b) the extent to which these changes result from a pattern of differential decline of processing components and abilities, and (c) the extent to which patterns of memory aging are influenced by physical health, activity life style, and personal belief variables.